Its easy to write these concerns off as nobody should actually buy these cards under the assumption that theyre going to maintain their value, its just a game, what did you expect, paying $500 for a piece of cardboard? or even, if you have enough money to blow on $100 Magic cards, then money shouldnt be enough of a problem for you for this to matter. The problem, of course, is that people grow and circumstances change
All of your Sagas reduce Excaliburs cost
The other Zurgo versions from Tarkir: Dragonstorm are much better for most decks and even as commanders, but lets not forget about the original big guy
These are all your chase cards, and all cards that people want to open packs for
Even when this happens, dual lands will continue to be a necessary part of most deck's manabases
With the Pixar release date still quite a while away, there's plenty of time to speculate over which characters will be the first to join Disney Lorcana